/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ANDROID_BASE_PARSEINT_H
#define ANDROID_BASE_PARSEINT_H

#include <errno.h>
#include <stdlib.h>

#include <limits>
#include <string>

namespace android {
    namespace base {

// Parses the unsigned decimal integer in the string 's' and sets 'out' to
// that value. Optionally allows the caller to define a 'max' beyond which
// otherwise valid values will be rejected. Returns boolean success; 'out'
// is untouched if parsing fails.
        template<typename T>
        bool ParseUint(const char *s, T *out,
                       T max = std::numeric_limits<T>::max()) {
            int base = (s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) ? 16 : 10;
            errno = 0;
            char *end;
            unsigned long long int result = strtoull(s, &end, base);
            if (errno != 0 || s == end || *end != '\0') {
                return false;
            }
            if (max < result) {
                return false;
            }
            *out = static_cast<T>(result);
            return true;
        }

// TODO: string_view
        template<typename T>
        bool ParseUint(const std::string &s, T *out,
                       T max = std::numeric_limits<T>::max()) {
            return ParseUint(s.c_str(), out, max);
        }

// Parses the signed decimal integer in the string 's' and sets 'out' to
// that value. Optionally allows the caller to define a 'min' and 'max
// beyond which otherwise valid values will be rejected. Returns boolean
// success; 'out' is untouched if parsing fails.
        template<typename T>
        bool ParseInt(const char *s, T *out,
                      T min = std::numeric_limits<T>::min(),
                      T max = std::numeric_limits<T>::max()) {
            int base = (s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) ? 16 : 10;
            errno = 0;
            char *end;
            long long int result = strtoll(s, &end, base);
            if (errno != 0 || s == end || *end != '\0') {
                return false;
            }
            if (result < min || max < result) {
                return false;
            }
            *out = static_cast<T>(result);
            return true;
        }

// TODO: string_view
        template<typename T>
        bool ParseInt(const std::string &s, T *out,
                      T min = std::numeric_limits<T>::min(),
                      T max = std::numeric_limits<T>::max()) {
            return ParseInt(s.c_str(), out, min, max);
        }

    }  // namespace base
}  // namespace android

#endif  // ANDROID_BASE_PARSEINT_H
